Hand-held wireless devices, such as cellular telephones, Personal Digital Assistants (PDAs), and more recently the new generation of mobile internet devices (MIDs) and smart phones are gaining widespread acceptance. In order to be competitive in the marketplace and to meet consumer demand, service providers continue to offer an ever expanding array of services and features.
PDAs, or more generally hand-held computers, were originally designed for use as personal organizers for storing notes, contact information, calendar dates and so forth. The current generation of MID hand-held devices additionally incorporates wireless and cellular technology and act as a phone for voice communications. Further, many allow users to access a variety of information and include services and features such as internet browsing, global positioning system (GPS) maps and driving directions, instant stock quotes, entertainment locators, email service, and a variety of multi-media music and video capturing and playback capabilities, to name a few.
Since such hand-held devices are by their nature small, command input has been challenging. Early generations of these devices used physical keys to type in data and commands. More recently, very good touch screens have been developed. However, whether physical keys or virtual keys on a screen they tend to be small and sometimes hard to navigate. Sometimes a stylus or other pointing stick may be used if the user's fingers is too big or lacks the necessary dexterity to hit the correct key. Further, keyboards and touch screens may be difficult to hold and operate with just one hand, even for inputting just basic functions. Thus an easier to operate input devices for mobile devices would be welcome.